Biometrics Authentication Device and Biometrics Authentication Method for Authenticating a Person with Reduced Computational Complexity

2. The biometrics authentication device of claim 1, wherein the biometric sensor includes at least one of a visible light sensor, a near infrared light sensor, a combined visible light and near infrared light sensor, and a time of flight camera.

4. The biometrics authentication device of claim 3, wherein the user guidance relates to moving the body part into a predefined posture as regards one or more of a relative distance, a relative orientation, and a gesture of the body part of the person.

5. The biometrics authentication device of claim 1, wherein the at least one characteristic geometric body part property further comprises one or more of a sum of the lengths of a set of fingers of a hand and a sum of the average widths of a set of fingers of a hand.

6. The biometrics authentication device of claim 1, wherein the at least one characteristic geometric body part property relates to one or more of a left hand, a right hand, a palm side of a hand, and a back side of a hand.

7. The biometrics authentication device of claim 1, wherein the predefined subsets of values overlap each other with a margin in accordance to an expected error of the at least one characteristic geometric body part property.

8. The biometrics authentication device of claim 1, wherein each of the predefined subsets of values includes a different interval of values for the at least one characteristic geometric body part property.

9. The biometrics authentication device of claim 1, wherein the processing unit is further configured to approve authentication of the person if the comparison finds a match based on a similarity measure between the biometric features of the body part of the person and the pre-stored biometric features of the body part of one of the registered persons.

12. The biometrics authentication device of claim 1, wherein the processing unit is configured to compare the biometric features of the body part of the person only to the pre-stored biometric features of the body parts of the registered persons in one and only one of the predefined subsets of values.

14. The biometrics authentication method of claim 13, wherein the biometric sensor includes at least one of a visible light sensor, a near infrared light sensor, and a time of flight camera for capturing the image data.

16. The biometrics authentication method of claim 13, wherein the at least one characteristic geometric body part property further comprises one or more of a sum of the lengths of a set of fingers of a hand and a sum of the average widths of a set of fingers of a hand.

17. The biometrics authentication method of claim 13, wherein the predefined subsets of values overlap each other with a margin in accordance to an expected error of the at least one characteristic geometric body part property.

20. The biometrics authentication device of claim 18, wherein each of the predefined subsets of values overlaps at least one other of the predefined subsets of values.